It's not an easy task to forget someone whom you really loved, if you forget then you should accept the fact that you didn't actually love them. Just be busy and you'll forget that person if it was just an attraction and not love.
Drugs
hmm idk 🤔 the typical way is to get someone else as a rebound to get over that someone, but don't do that, it's unethical and asshole-ish 😂
Tbh you can't..but You can change your focus to something more important like your career